So why should you buy a DVD boxed set of a series that was cancelled in only its second season? Because it is one of the most intelligently scripted SF series of recent years. Because its multiple-narrative flash-forwards are as dazzlingly wrong-footing as they are compelling. Because the cast is uniformly excellent across the board.

Take the bloodless and literally inhuman superbitch of Shirley (Garbage) Manson’s Catherine Weaver (think Dallas with poly-metal alloy shoulder pads). Her exchanges with ex-FBI agent and hired hand James Ellison (Richard T Jones) are superbly scripted, the ultimate godless rationalist stirr­ing it up in the still centre of this man of faith, their battleground the blank programmable silicon page that is resurrected Termin­ator John Henry (Gareth Dillahunt, delivering a chilling, childlike techno-Frankenstein monster).  

Or the sadomasochistic love and machinations between time-travell­ing, post-Judgement Day warriors Reese and Jesse (Brian Austin Green and Stephanie Jacobsen, their onscreen chemistry Nitro and Glycerine).

And then there’s the even more volatile core trio of Sarah Connor (Lena Headey, utterly convincing while utterly different to the memorable superhuman matriarch Linda Hamilton gave us in Termin­ator 2), an all-too human mother who absolutely will stop at nothing to protect her Messiah-like son, John Connor (Thomas Dekker). And last but not least, John’s protector Terminator, Cameron (Summer Glau), as sublime in name as her onscreen cyborg presence. Her mirthless gnomic utterances – “Sometimes they go bad. No one knows why,” she says after dispatching a hostile Terminator – are pitch-perfect.

The final episode, like the whole of the series before it – great dialogue, great character dynamics, great action – is a magnificent mind-screw towards not what might have, but should have, been: a future of infinite possibilities, which is what it now, ironically, continues to be. Rumours, rants and conspiracy theories abound as to why it was cancelled. I signed umpteen petitions online to save it myself. Thomas Dekker even posted a YouTube plea on the eve of the series’s destruction. In the end, it probably came down to nothing more mysterious than ratings. Joss Whedon’s Dollhouse was also up for the chop but, despite its lacklustre viewing figures, the suited assassins kept it alive, probably because of its Buffy-drawn fanbase. It too has now been cancelled due to continued poor ratings.

This second season of Termin­ator: The Sarah Connor Chronicles is even better than the first, and, that rare thing, a TV spin-off from a film franchise that not only honours but improves upon the mythology of the (James Cameron) originals.

The TV annals are strewn with pearls that fell among executive swine and Terminator: The Sarah Connor Chronicles is one of them. The only reason not to buy this is because it might be putting money in said suited assassins’ pockets. But in this case, needs really must.